S1, E3: Scientists are studying cats in more detail than ever before, and what they are discovering is truly groundbreaking. Join the scientists in the field, testing new theories and challenging the conventional ideas about cats. New approaches and new technologies are allowing an intimate look at their previously hidden lives. This new age of discovery is revealing there is still so much to learn about the cat family. Using high-tech collars, Professor Alan Wilson has discovered it is not straight-line speed that is a cheetah's greatest weapon but their ability to brake, change direction and accelerate. His research is rewriting what we understand about the fastest animal on land. This is also a crucial time for cat conservation - most are threatened, facing extreme habitat loss and conflict with humans. Yet there are many positive stories of cats bouncing back from the brink, showcasing the tireless work of cat conservationists fighting to protect them. Just five years ago the Iberian lynx was considered the rarest cat on the planet. Now, due to a groundbreaking captive-breeding programme, lynx numbers are increasing in the wild. A huge amount of effort is going into breeding and releasing these stunning cats, and all the hard work is now paying off.